Wrought-iron davit boom



, v l. ALTMLLER wRoUGHIj I RoN DAvIT Boom Flled Oct 1 1923 April 15 1924 Patented Apr. l5, 1924.

PAUL ALTMLLER, OF KIEL-KROUSHAGEN, GERMANY, ASSIGNOR TO FRIED. KRUPP AKTIENGESELLSCHAFT GERMANIAWER-FT, OF KIEL-GAARDEN, GERMANY.

WROUGHT-IR'N VJDAVI'I BOOM.

Application filed October 1, 1923. Serial No. 666,006.

To all whom t may concer/n.:

Be it known that I, PAUL ALTMLLER, residing at Kiel-Kronshagen, Germany, a citizen of the German Republic, have invented a certain new and useful Improve ment in wWrought-Iron Davit Booms, of which the following is a specification.

This invention relates to a wrought iron davit boom for boat launching devices.

An embodiment of the subject-matter of the invention is illustrated in the accompanying drawing, the three Figures l, 2 and 3 of which show side elevations of the davit boom in three diierent sections of manufacture.

The finished davit boom (Fig. 3) consists of two parts. One part is formed by the upwardly tapering wrought iron jib arm A which is of circular cross-section and which has integrally formed with it the spokes al, a2 which are of rectangular cross-section. The other part is formed by the toothed sector B which is preferably made of cast steel; when the boat launching device is assembled the sector meshes with a rack bar-not shown in the drawing-which is rigidly arranged on the davit support and on which the sector rolls oil during the operation of' the davit.

The invention resides in that the boom A., al, 0:2 is made by first giving to the saine by 'forging the shape, shown in Fig. l, which tapers upwardly and downwardly from the bore C which serves to receive the rocking shaft of the davit boom, the portion lying above the bore C being of circular cross-section and the portion below the same being of a substantially quadratic cross-section. The stronger lower portion is then slotted along the line m-g/ and the arms al and a2 which are thus formed and which have a rectangular cross-section decreasing in size towards the lower ends, are bent away from each other as shown in Fig. 2. They form the two spokes oi" the toothed rim B which is rigidly connected to the ends of the spokes a1, o2 by means et rivets or screws, as is io be seen from Fig. 3. The angular position of the arms o1, o2 with relation to each other and to the arm A may be determined in accordance with the circumstances. With the boom shown in Fig. 3, the spoke al forms a direct linear extension of the arm A.

Claim.

A wrought iron davit boom with a separately made toothed sector, having the jib arm and the spokes for the toothed sector formed ol" a wrought. iron piece, the lower portion of this piece being stronger than its upper portion, the said spokes being made out oi the stronger lower portieri by slotting the same and bending the arms thus formed away from each other, and the toothed sector' being rigidly connected with the ends of these arms.

The foregoing specification signed at Hamburg, Germany, this 27th day of August, 1923.

PAUL ALTMULLER. 

